Final Words

The iPhone 5s is quite possibly the biggest S-update we've ever seen from Apple. I remember walking out of the venue during Apple's iPhone 5 launch and being blown away by the level of innovation, at the platform/silicon level, that Apple crammed into the iPhone 5. What got me last time was that Apple built their own ARM based CPU architecture from the ground up, while I understand that doesn't matter for the majority of consumers - it's no less of an achievement in my eyes. At the same time I remember reading through a sea of disappointment on Twitter - users hoping for more from Apple with the iPhone 5. If you fell into that group last time, there's no way you're going to be impressed by the iPhone 5s. For me however, there's quite a bit to be excited about.

The A7 SoC is seriously impressive. Apple calls it a desktop-class SoC, but I'd rather refer to it as something capable of competing with the best Intel has to offer in this market. In many cases the A7's dual cores were competitive with Intel's recently announced Bay Trail SoC. Web browsing is ultimately where I noticed the A7's performance the most. As long as I was on a good internet connection, web pages just appeared after resolving DNS. The A7's GPU performance is also insanely good - more than enough for anything you could possibly throw at the iPhone 5s today, and fast enough to help keep this device feeling quick for a while.

Apple's move to 64-bit proves it is not only committed to supporting its own microarchitectures in the mobile space, but also that it is being a good steward of the platform. Just like AMD had to do in the mid-2000s, Apple must plan ahead for the future of iOS and that's exactly what it has done. The immediate upsides to moving to 64-bit today are increased performance across the board as well as some huge potential performance gains in certain FP and cryptographic workloads.

The new camera is an evolutionary but much appreciated step forward compared to the iPhone 5. Low light performance is undoubtedly better, and Apple presents its users with an interesting balance of spatial resolution and low light sensitivity. The HTC One seemed to be a very polarizing device for those users who wanted more resolution and not just great low light performance - with the 5s Apple attempts to strike a more conservative balance. The 5s also benefits from the iOS's excellent auto mode, which seems to do quite well for novice photographers. I would love to see full manual control exposed in the camera UI, but Apple's auto mode seems to be quite good for those who don't want to mess with settings. The A7's improved ISP means things like HDR captures are significantly quicker than they were on even the iPhone 5. Shot to shot latency is also incredibly low.

Apple's Touch ID was the biggest surprise for me. I found it very well executed and a nice part of the overall experience. When between the 5s and the 5/5c, I immediately miss Touch ID. Apple is still a bit too conservative with where it allows Touch ID instead of a passcode, but even just as a way to unlock the device and avoid typing in my iCloud password when downloading apps it's a real improvement. I originally expected Touch ID to be very gimmicky, but now I'm thinking this actually may be a feature we see used far more frequently on other platforms as well.

The 5s builds upon the same chassis as the iPhone 5 and with that comes a number of tradeoffs. I still love the chassis, design and build quality - I just wish it had a larger display. While I don't believe the world needs to embrace 6-inch displays, I do feel there is room for another sweet spot above 4-inches. For me personally, Motorola has come the closest with the Moto X and I would love to see what Apple does with a larger chassis. The iPhone has always been a remarkably power efficient platform, a larger chassis wouldn't only give it a bigger, more usable screen but also a much larger battery to boot. I'm not saying that replacing the 4-inch 5s chassis is the only option, I'd be fine with a third model sitting above it in screen size/battery capacity similar to how there are both 13 and 15-inch MacBook Pros.

The lack of 802.11ac and LTE-A support also bother me as the 5s is so ahead of the curve elsewhere in silicon. There's not much I can see to either point other than it's obvious that both will be present in next year's model, and for some they may be features worth waiting for.

At the end of the day, if you prefer iOS for your smartphone - the iPhone 5s won't disappoint. In many ways it's an evolutionary improvement over the iPhone 5, but in others it is a significant step forward. What Apple's silicon teams have been doing for these past couple of years has really started to pay off. From a CPU and GPU standpoint, the 5s is probably the most futureproof of any iPhone ever launched. As much as it pains me to use the word futureproof, if you are one of those people who likes to hold onto their device for a while - the 5s is as good a starting point as any.

You consider your comment 'technical argumentation'? It's not....it's your 'opinion'. I think you can rest assured Anand's site is geared much more to those of us interested in technology and less interested in being a 'fanboy'. In fact....so far reading through the comments, you're the first to bring that silly cliché up, "Fan Boy".A drowning man will hold on to anything to help save himself :)Reply

Good comment - I'm equally unimpressed by the comparison of a real phone with a Bay Trail tablet development board which has significantly higher TDP. And then calling it a win for Bay Trail based on a few rubbish JS benchmarks is even more ridiculous. These are not real CPU benchmarks but all about software optimization and tuning for the benchmark.

Single threaded Geekbench 3 results show the A7 outperforming the 2.4GHz Bay Trail by 45%. That's despite the A7 running at only 54% of the frequency of Bay Trail! In short, A7 is 2.7 times faster than BT and on par/better than HasWell IPC...Reply

not trying to dismiss A7's cpu core, it's an amazing silicon and significantly steps up against A6, but is there a possibility that the geekbench3 is unfit to gauge average cross-ISA cross-OS cpu performance... To me, the likelihood of this is pretty high.Reply

Comparing different ISAs does indeed introduce inaccuracies due to compilers not being equal. Cross OS is less problematic as long as the benchmark doesn't use the OS a lot.

It's a good idea to keep this in mind, but unfortunately there is little one can do about it. And other CPU benchmarks are not any better either, if you used SPEC then performance differences across different compilers are far larger than Geekbench (even on the same CPU the difference between 2 compilers can be 50%)...Reply

"The AES and SHA1 gains are a direct result of the new cryptographic instructions that are a part of ARMv8. The AES test in particular shows nearly an order of magnitude performance improvement".

Your comment: "in reality the encryption workloads are handled in a fundamentally different way in the two modes [...] a mixed bad into one falsely advertising performance gains attributed to 64bit execution and not to the hardware implementations as it should"

Maybe actually read the article?

"The FP chart also shows no miracles, wider SIMD units result in almost 2x the score in few tests, nothing much in the rest"Exclude those test and you're still looking at 30% improvement. 30% increase in performance from a recompile counts at "nothing much" in what world?Reply

My point was encryption results should not have been included in the chart and presented as "benefits of 64bit execution mode" because they aren't.

Also those 30% can easily be attributed to other incremental upgrades to the chip, like faster memory subsystem, better prefetchers and whatnot. Not necessarily 64bit execution, I've been using HPC software for years and despite the fact x64 came with double the registers, I did not experience any significant increase in the workloads I use daily - 3D rendering, audio and video processing and multiphysics simulations. The sole benefit of 64bit I've seen professionally is due to the extra ram I can put into the machine, making tasks which require a lot of ram WAY FASTER, sometimes 10s even 100s times faster because of the avoided swapping.

Furthermore, I will no longer address technically unsubstantiated comments, in order to avoid spamming all over the comment space.Reply

""30% can easily be attributed to other incremental upgrades to the chip". Wouldn't the 32-bit version benefit from those as well?"

This may be correct. Unless I am overlooking execution mode details, of which I am not aware, and I expect neither are you, unless you are an engineer who has worked on the A7 chip. I don't think that data is available yet to comment on it in detail.

But you are not correct about encryption results, because it is a matter of extra hardware implementation. It is like comparing software rendering to hardware rendering, a CPU with hardware implementation of graphics will be immensely faster at a graphics workload, even if it is the same speed as the one that runs graphics in software. If anything, the architecture upgrades of the A7 chip can at best result in 2x peak theoretical performance improvement, while the AES test shows 8+x improvement. This is because the performance boost is not due to 64 bit mode execution, but due to the extra hardware implementation that is exclusively available in that mode.Reply